Electric switch operating mechanism



Aug. 7, 1934. R. PAXTON 1,969,576

ELECTRIC SWITCH OPERATING MECHANISM Filed Nov. 30. 1931 Inventor;Robert; Paxton,

His Attow-hes Patented Aug. 7, 1934 ELECTRIC SWITCH OPERATING MECHANISMv Robert Paxton, Drexel Hill, Pa., assignor to General Electric Company,a corporation of New York Application November 30, 1931, Serial No.577,880

2 Claims.

My invention relates to electric switch operating mechanism, moreparticularly to mechanism for eifecting selective operation of circuitbreakers as in single phase switching.

A polyphase electric power transmission system may, under certainconditions, be controlled to advantage by selective operation of thesingle phase circuit breakers. This selective control known as singlephase switching may be of particular value in maintaining continuity ofservice as in .the case of a temporary single phaseto-ground fault. In-polyphase systems wherein the phase circuit breakers are tied togetherby a common operating mechanism and close and i5 trip in unison, aphase-to-ground fault would result in complete interruption of thesupply. In case of single phase switching, however, it is possible totrip out the breaker in the phase having a temporary fault and carry theunbalanced load on the remaining phases for a limited time. In

the meantime the fault may have cleared permitting reclosing of thebreaker.

The principal object of my invention is the provision of improvedmechanism for single phase switching.

My invention will be more fully set forth in the following descriptionreferring to the accompanying drawing, and the features of noveltywhich.

characterizemy invention will be pointed out with particularity in theappended claims forming a part of this specification.

Referring to the drawing, Fig. 1 is a view, partly in perspective, ofoperating mechanism embodying my invention, and Fig. 2 is an enlargedfragmentary view'of details shown in Fig. 1.

In the arrangement shown, a circuit breaker generally indicated at 1comprises one of the phase breakers of a three phase power transmissionsystem. Since the construction and operation of the other breakers areidentical, a de tailed disclosure and description thereof may be omittedin the interest of clearness. The operating mechanism for the circuitbreakers is generally indicated at 2 and comprises suitable motivemeans, as an electric motor 3, for transmitting movement to the switchmechanism through the well known centrifugal or flyball operator 4.

To this end the flyball operator 41s pivotally connected to a crank 5which is suitably keyed or pinned to the main operating shaft 6.Energization of the motor 3 and extension of the rapidly rotatingfiyball linkage causes counterclockwise rotation of the shaftand-tensioning of a spring "I, which is fixed at one end '7' andconnected at the other end to a lug a likewise pinned on the shaft 6.The flyball linkage 4 is shown in the initial or reset position towardswhich it is normally biased by the resetting spring 7. In

other words, the spring -'7 effects resetting of the extended flyballlinkage after each circuit closing operation.

For the purpose of transmitting closing movement from the main shaft 6to the breakers of the respective phases indicated by A, B, and C, aplurality of toggles, one for each breaker, are arranged to bestraightened to an overset locking position by rotation of the, shaft 6,each toggle being free to collapse and permit opening of thecorresponding breaker independently of the other toggles. To this end,the breaker 1 of B phase, for example, is operatively. connected to theshaft 6 by a toggle 9-10, the toggle arm 10 including a collar 11 whichis mounted to free rotative movement on the shaft 6. The toggle joint 12is locked in the overset position by the offset lug 13 carried by thearm 10 so that an'initial tripping impulse is necessary'to causecollapse of the toggle. The toggle arm 9 is connected to the switchactuating rod 14 through a bellcrank 15 pivotally mounted on a fixedshaft 16. The tripping impulse may be applied in any suitable manner, atripping solenoid 17 being shown by way of example for this purpose. Thetripping mechanism shown is simplified in the interest of clearnesssince it forms no part of the present invention. It will therefore beapparent that the mechanism connected to the individual, breakers may beof the well-known trip-free type.

For the purpose of permitting tripping andreclosing'of a single breakerirrespective of the fact that the other breakers remain closed, a lostmotion connection is provided between the shaft 6 and the individualtoggles. This lost motion connection comprises, in the case of the Bphase toggle, an offset lug or equivalent member 18 secured to the crank.5 and arranged to engage the toggle arm 10 in closing the breaker. Thelost motion connection for each of the phases A and C includes a collar19 pinned as at 20 to the shaft 6 and provided with an offset lug 21 forengaging the corresponding toggle arm 10. This construction is bestshown in Fig. 2 wherein the parts are spaced in order clearly toillustrate the manner of cooperation.

It will be noted that the toggle arm 10, which is loosely mounted on theshaft 6, is positively driven in but one direction by the lug 21 carriedby the fixed collar 19. Rotation of the shaft 6 in the oppositedirection simply moves e the lug 21 away from the toggle without at-Iecting the position of the same.

Assuming, therefore, the toggle of the B phase mechanism to be in theposition shown, the other toggles being closed, energization of themotor 3 and extension of the fiyball linkage 4 will cause rotation ofthe crank 5 and straightening of the toggle 9-l0 through the connectionabove referred to. The collars 19 associated with the toggles of the Aand C phases merely rotate without engaging the corresponding togglearm. As the toggle is straightened the-actuating rod 14 of the B phasebreaker is lowered, causing closing of the breaker.

Any suitable type of breaker may, of course, be employed, and by way ofexample there is shown a circuit breaker of the explosion chamber typecomprising a vertically movable bridging member 22 coacting with thestationary contact structure within so-called explosion pots 23 and 24separated by an insulating bracing member 25. The lift rod 26 of thebreaker is connected to the actuating rod lithrough the well knownparallel linkage mechanism 27. The above circuit breaker structure ismounted in a manner well known in the art in a steel tank'containingoil.

The operation of the mechanism may be summarized as follows: Assumingthe polyphase system to be in normal operation and all three breakersclosed, the corresponding toggles 9--10 will each be in the oversetlocking position and the fiyball linkage 4 will be in the deenergizedreset position. In the event of a phase-to-ground fault on B phase forexample, the tripping solenoid 17 is energized, kicking thecorresponding toggle over-center and causing collapse thereof to theposition shown. The collapse of the toggle is assured by forces, asgravity for example,

normally biasing the circuit breaker towards open position. Since thelug 18 is in the reset position, the toggle 9--10 is free to trip openin-- dependently of the other toggles. Clearance of the fault within ashort time permits reclosing of the B phase breaker which may be readilyaccomplished by energizing the motor 3 and straightening the toggle 910ofthe open breaker. Closing of the B phase breaker is effected by themotor independently of the other breakers since the collars 19 mayrotate to the completely closed position before the lugs 21 engage thecorresponding toggle arms 10. In the same manner the breakers may beclosed simul taneously, after which the motor 3 is deenergized and theoperating linkageii'is reset so that selective reclosure of the phaseswitches may be effected.

It should be understood that my invention is not limited to specificdetails of construction and arrangement thereof herein illustrated, andthat changes and modifications may occur to one skilled in the artwithout departing from the spirit of my invention.

What I claim as'new and desired to secure by Letters Patent of theUnited States is:

1. Polyphase switch operating mechanism for a plurality of single phasecircuit breakers comprising an operating motor, means including aplurality of toggles and a shaft actuated by said motor operativelyconnecting said motor to each of said breakers, means secured to saidshaft for engaging only the toggles of breakers to be closed, rotationof said shaft in one direction causing straightening of one or more ofsaid toggles, and resilient means biasing said shaft independently ofsaid toggles in the opposite direction for resetting said mechanismafter said toggle operation.

2. Switch operating mechanism for a plurality of single phase circuitbreakers comprising a motor and centrifugal operating linkage, a shaftdirectly connected to said linkage arranged to be rotated in onedirection upon extension of said linkage, an actuating toggle for eachbreaker operatively connected between the same and said shaft, eachtoggle having an arm mounted for free rotative movement on said shaft,lugs individual to each toggle fixed to said shaft for moving thecorresponding toggle arm to the straightened position, a trippingsolenoid coacting with each toggle for causing collapse thereof, and aspring for rotating said shaft in the opposite direction to its initialposition after deenergization of said operating motor.

ROBERT PAXTON.

